1. Field of the Invention
The present invention relates to method and apparatus for producing sheet members by successively joining sheet materials having a predetermined length.
2. Description of Related Art
In order to produce integral sheet members such as carcass plies or belt plies of pneumatic tires, it has been a conventional practice that a predetermined amount of sheet material is fed from a predetermined feeding position to a conveyor in a predetermined direction, and is cut into a strip having a predetermined length. Sheet members are successively formed by driving the conveyor to move the strips forwards, and joining the trailing end of a preceding stip to the leading end of a succeeding strip. The sheet members so produced are wound into a roll, transferred to a storage space and stored therein. When the sheet members are to be used, the roll is removed from the storage space to a location in front of a drum, e.g., tire building drum, and unwound from the roll and wound onto the drum.
The conventional method explained above allows continuous production of only one end of sheet members. It is highly desirable to improve the manufacturing flexibility.
It is therefore a primary object of the present invention to provide improved method and apparatus for continuously producing a plurality of types of sheet members.
According to a first aspect of the present invention, there is provided a method for producing sheet members, wherein integral sheet members are produced by repeating the steps of feeding a predetermined amount of sheet material to a conveyor from a feed position on one side of the conveyor, cutting the sheet material to form a preceding strip which is transferred by the conveyor along a predetermined path, and joining a leading end of a successive strip to a trailing end of the preceding strip. The method according to the present invention further comprises the steps of: branching the transfer path of the preceding sheet strip in at least two directions and thereby providing at least two types of preceding strips; and connecting the leading end of the succeeding strip to the trailing end of the preceding strip of a selected type, thereby continuously producing at least two kinds of sheet members.
According to a second aspect of the present invention, there is provided an apparatus for producing integral sheet members, comprising: a main conveyor for transferring a strip which is made from a sheet material; a feed means arranged on one side of the main conveyor, for feeding a predetermined amount of the sheet material to the main conveyor; a cutter for cutting the sheet material in front of the main conveyor to form a strip to be transferred by the main conveyor; at least two branch conveyors connected to a downstrean side of the main conveyor so that the strip transferred by the main conveyor has a transfer path which is branched into at least two directions to provide at least two types of preceding strips; a joining mechanism for joining a leading end of a succeeding strip to a trailing end of the preceding strips of a selected type at a joining position on the main conveyor: and a controller for controlling the operation of the main conveyor, the branch conveyors, the feed means, the cutter and the joining mechanism, said controller selectively causing the trailing ends of the branched strips to be moved toward and away from the joining position, so as to continuously produce at least two kinds of sheet members.
With the above-mentioned method and apparatus according to the present invention, a predetermined amount of sheet material is fed to a conveyor from a feed position on one side of a conveyor, and is cut to form a preceding strip which is transferred by the conveyor along a predetermined path. The transfer path of the preceding sheet strip is branched into at least two directions, to thereby provide at least two types of preceding strips. The leading end of a successive strip is joined to the trailing end of a preceding strip of a selected type. In this way, at least two kinds of sheet members can be produced continuously and highly efficiently, with an improved manufacturing flexibility.
Further advantageous embodiments of the method and apparatus according to the present invention are defined by the dependent claims.